October Political Discussion Group Packet
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OCTOBER POLITICAL DISCUSSION GROUP PACKET 1 Life on Mars: NASA finds first hint of alien life Sarah Knapton The Telegraph September 28, 2015 The first hints of life on Mars have been discovered by NASA. Intriguing ‘burps’ of methane have been recorded by the Curiosity Rover which may have been produced by bacteria. Most methane on Earth is produced as a waste gas by living organisms. Curiosity has previously found water bound in the fine soil of the Red Planet, believed to be crucial to life. But if the existence of living, breathing microbes is confirmed, it will be the first evidence of life outside Earth. “What is interesting is that these spikes of methane are coming and going. They are transient,” said Dr. Paul Mahaffy at NASA. “At the moment we can’t really tell anything, but these burps are intriguing. We have to keep an open mind. “We don’t want to eliminate anything, and potentially it could indicate life or evidence of ancient methane trapped which could show ancient life. “But it’s interesting to think about why it comes and goes. It seems to be suggestive of a localized source.” NASA claims that with more readings it would be possible to test isotope levels which would prove if the emissions came from a biological source. Mars is the fourth planet from the Sun and is around half the diameter of Earth. However it is less dense than Earth, having around 15 per cent volume and about 11 per cent mass. 2 Its red appearance is caused by iron oxide, which gives blood and rust their color. Scientists are divided on what caused the reddening. Some think rain storms billions of years ago caused iron on the surface to rust. Curiosity has been exploring Mars’ Gale Crater, a 96 mile wide depression caused by an asteroid strike, since 2012. Previous satellite observations have detected unusual plumes of methane on the planet, but none as extraordinary as the sudden "venting" measured at the crater. The new discovery, reported in the journal Science, came from gas samples by Curiosity's Tunable Laser Spectrometer (TAS), an instrument that uses intense light to carry out chemical analysis. The low background level of methane can be explained by the Sun's rays degrading organic material possibly deposited by meteors, said the NASA scientists But the readings in a 300 meter squared area spiked 10-fold over a period of just 60 Martian days. By the time Curiosity had travelled a further kilometer, the higher methane levels had disappeared. In their paper, the US scientists led by Dr. Chris Webster, from Nasa's Jet Propulsion Laboratory in Pasadena, California, wrote: "The persistence of the high methane values over 60 sols (Martian days) and their sudden drop 47 sols later is not consistent with a well-mixed event, but rather with a local production or venting that, once terminated, disperses quickly." Life is the chief producer of methane on Earth, but there are many non-biological processes that can also generate the gas. It could have come from an asteroid strike. Asteroids contain methane which could be released on impact. However, no recent strikes have been recorded near Gale Crater. The short time-scale of the methane spikes also means that it is unlikely the gas was released from volcanic deposits trapped in ice, called clathrates. Nor did it appear to come from the release of gaseous methane that had become bound to the soil. 3 The NASA authors are cautious about jumping to conclusions, but conclude that "methanogenesis" - the formation of methane by microbial bugs known as methanogens - may be one answer to the riddle. They wrote: "Our measurements spanning a full Mars year indicate that trace quantities of methane are being generated on Mars by more than one mechanism or a combination of proposed mechanisms - including methanogenesis either today or released from past reservoirs, or both." Gale Crater was created when a large meteor struck the planet 3.5 billion to 3.8 billion years ago. Earlier this month the Curiosity Rover discovered that Mount Sharp, a mound of rock in the middle of Gale Crater was built by sediments deposited in a large lake bed tens of millions of years ago. The crater itself was once a vast ocean, experts believe. An analysis of rocks at the bottom of a mountain in the middle of the crater show that water flowed at different levels over the course of millions of years. There are still substantial amounts of water ice at the Martian poles. The rover has now reached the base of Mount Sharp and over the coming months will begin a slow climb. Scientists are especially keen to explore the mountain because its sedimentary layers provide tantalizing snapshots of Martian history. The question of whether there is, or was, life on Mars may finally be answered by the European Space Agency's ExoMars mission, which will land a 300kg rover on the Red Planet in 2019. ExoMars will be equipped with a two-meter drill and the ability to detect biomarkers of life. It will not be heading for Gale Crater, however. Because it will land with less precision than Curiosity, the crater and its mountain are considered too potentially hazardous. “We just need to keep looking,” added Dr Mahaffy. 4 Life on Mars? NASA makes incredible discovery of running water that could sustain aliens or humans Mirror September 28, 2015 Jasper Hamill NASA claims to have found evidence of running water on Mars - which could suggest alien lifeforms have lived on the planet. In a study, researchers said flowing liquid water is almost certainly responsible for mysterious features on the surface of the planet that change with the seasons. Satellite images have identified narrow streaks, typically less than five metres (16.4 ft) wide, that appear on slopes during warm seasons, lengthen, and then fade when conditions become cooler. Experts have speculated that water might be involved in the formation of the gully-like features, known as recurring slope lineae (RSL), but only now has evidence supporting the theory come to light. A new high resolution technique has revealed that RSLs at four locations on Mars contain salt minerals that precipitate from briny water. The salts, which are absent from the surrounding terrain, are thought to have been left by water flowing down the sides of hills or crater rims. NASA wrote: "Water is essential to life as we know it. The presence of liquid water on Mars today has astrobiological, geologic and hydrologic implications and may affect future human exploration." 5 Writing in the journal Nature Geoscience, the scientists led by Phd student Lujendra Ojha, from the Georgia Institute of Technology in Atlanta, US, concluded: "Our findings strongly support the hypothesis that recurring slope lineae form as a result of contemporary water activity on Mars." If confirmed the discovery has major implications for the chances of finding life on Mars, and future human exploration of the Red Planet. Mars is a cold barren desert today but is thought to have been warmer and wetter billions of years ago, with a thicker atmosphere, rivers and oceans. Much of the planet's water is believed to have evaporated into space, but some remains locked in the polar icecaps and possibly in pockets underground. The new research is based on an analysis of spectral data from the American space agency Nasa's Mars Reconnaissance Orbiter spacecraft. Breaking down reflected light into its different wavelengths provides a chemical "fingerprint" of what a substance is made of. The Mars scientists devised a new method that allowed chemical signatures to be extracted from individual image pixels, providing a much higher level of resolution than had been achieved before. At four locations, Palikir Crater, Horowitz Crater, Hale Crater, and Coprates Chasma - a huge Martian canyon - they found evidence of RSL salt deposits. The most common salts were magnesium perchlorate, magnesium chlorate and sodium perchlorate, all of which are consistent with flowing briny water. Just where the water has come from still remains an unsolved mystery. Theories include the melting of near-surface ice, absorption from the thin Martian atmosphere, and seasonal discharges from local aquifers, layers of water-bearing rock. 6 "It is conceivable that RSL are forming in different parts of Mars through different formation mechanisms," said the scientists. Dr. Joe Michalski, a Mars expert at London's Natural History Museum London, said: "These results provide strong evidence that salty water occasionally flows on the Martian surface, even today. "We know from the study of extremophiles on Earth that life can not only survive, but thrive in conditions that are hyperarid, very saline or otherwise 'extreme' in comparison to what is habitable to a human. In fact, on Earth, wherever we find water, we find life. "This finding is yet another example of water on Mars, but a hugely important one because it points to environments that could potentially be habitable to certain kinds of bacteria, even today." 7 Colonies in Space Richard Gott New Scientist September 8, 2007 Will we plant colonies beyond the Earth before it is too late? WHY send astronauts to other worlds? After all, some would argue that robots are far better suited to the extremes of space. Automated probes offer a cheaper and safer way to explore the solar system, they say -- just look at the success of NASA's Mars Rovers and the Huygens probe on Titan. Such missions justify their expense by the boost they provide to human knowledge. By contrast, proponents of human exploration invoke a more romantic argument: the human spirit's desire to tread new land, see new sights or climb virgin peaks, simply "because they are there".